When an electrical characteristic test of a test object such as a semiconductor wafer or the like is performed by using a probe card, for example, tip positions of probes of the probe card are detected by a camera for capturing images thereof and, then, the probes are made to contact with electrodes of the test object for the electrical characteristic test. In case the tip positions of the probes are detected by the camera, it takes a long time to focus the camera on the ends of the probes, thereby increasing time required to align the test object with the probe card. Therefore, the tip position of the probes is conventionally carried out for a few representative probes. However, in case of fine electrodes, parts of probes may not be properly aligned with the electrodes. Therefore, if possible, it is desirable to detect the tip positions of all of the probes for the alignment between the probes and the wafer.
Further, since various probe cards are developed by a plurality of probe card makers, there are a need to develop a dedicated algorithm for recognizing three-dimensional images of the probes, which incurs considerable costs. Therefore, if the probes can be transcribed on a two-dimensional film, an algorithm can be easily developed.
Therefore, Japanese Patent Laid-open Application No. 2001-189353 (hereinafter, referred to as Reference 1) discloses therein a method and a device for shortening the time needed for inspecting probes. In a technique disclosed therein, probe marks of probes in a probe card are transcribed on a deformable object before the test is carried out and then, insertion depths of the probes into electrodes are obtained based on the opening width of the probe marks, thereby shortening a time required for position-aligning the probes with the electrodes. Further, as for a device for measuring the size of the probe marks and the insertion depths of the probes, a position sensor using an electrostatic capacitance is proposed in Reference 1. Moreover, referring to Reference 1, X and Y coordinates of the probes are detected by using the position sensor having electrodes arranged in a matrix form.
Furthermore, Japanese Patent Laid-open Application No. 2005-308549 (hereinafter, referred to as Reference 2) discloses therein a film for adjusting positions of probes, the film being made from elastomer composition. Herein, the probes are made to contact with the film for adjusting positions of the probes, thus forming probe marks thereon. After a positional relationship between the probe marks and electrodes of an integrated circuit is checked, the positions of the probes are adjusted based on the positional relationship therebetween, if necessary.
Besides, Japanese Patent Laid-open Application No. H2-224260 (hereinafter, referred to as Reference 3) discloses therein a position alignment method. In this method, directions and preset positions of probes are recognized by using camera to detect probe marks of the probes on a dummy wafer.
In addition, Japanese Patent Laid-open Application No. 2005-079253 (hereinafter, referred to as Reference 4) discloses therein an inspecting method. In this method, thermally expanded probes are made to press-contact with a transcription sheet disposed on a support next to a mounting table, thereby leaving probe marks thereon. After the probe marks on the transcription sheet are detected, the thermally expanded probes are position-aligned with the wafer.
Further, Japanese Patent Laid-open Application No. H4-330750 (hereinafter, referred to as Reference 5) discloses therein a method for inspecting a semiconductor wafer. In this method, testing probes leave probe marks on a plate provided on a mounting table, the plate being formed of a transparent resin member. Next, a driving unit is driven based on image information on the probe marks, so that the testing probes are position-aligned with a semiconductor wafer on the mounting table.
Moreover, Japanese Patent Laid-open Application No. H7-147304 (hereinafter, referred to as Reference 6) discloses therein a method for inspecting probes. In this method, a position of a mounting table in X, Y and θ directions is sensed based on a cross-shaped mark serving as a reference point in X and Y directions, the cross-shaped mark being formed at a center of a small alignment member provided next to the mounting table. A position of the mounting table in Z direction is sensed by a electrostatic capacitance sensor and a conductive thin film formed at a periphery of the cross-shaped mark. During an initial test, a probe mark formed on an electrode pad of an initial chip is detected by a CCD camera. Whether post tests will be performed or not is determined based on the detected probe mark.
In case of the technique of Reference 1, although the tip positions and the insertion depths of the probes can be checked based on the probe marks formed on the deformable object, a positional relationship between the probes and a test object is not checked by the deformable body. Further, although Reference 2 discloses therein that it is possible to check the positional relationship between, by making the probe marks on the film for probe position adjustment, the probe mark and the electrodes of the integrated circuit, but it does not embody any technique for checking the positional relationship between the probe marks and the electrodes.
In case of the techniques of References 3 and 4, the probe marks formed on the dummy wafer or the transcription sheet are detected one after another by the imaging unit while moving the mounting table having thereon the wafer. Thus, as the frequency of movement of the mounting table increases, the error in the moving amount is accumulated. Consequently, as the test time passes, the detection accuracy becomes poorer.
The technique of Reference 5 is same as those of References 3 and 4 in that the positions of the probes are detected based on the probe marks formed on the plate provided on a part of the mounting table. In case of the technique of Reference 6, the probe mark formed on the electrode pad of the initial chip is detected during the initial test and, then, whether post tests will be performed or not is determined based on the detected probe mark. Hence, it is not possible to check in advance the positional relationship between the probes and the electrode pads on the entire surface of the wafer.